Unit B Section 1.2

Question 1

melting

Answer 1

solid to liquid

Question 2

freezing

Answer 2

liquid to solid

Question 3

condensation

Answer 3

gas to liquid

Question 4

evaporation

Answer 4

liquid to gas

Question 5

deposition

Answer 5

gas to solid

Question 6

sublimation

Answer 6

solid to gas

Question 7

Properties are characteristics that can be used to describe a substance.
All matter has two types of properties:

Answer 7

Physical :
(Characteristics that can be noticed when the substance is alone ).

Chemical:
(Characteristics that can be seen when the substance interact with other substances)

Question 8

List Physical Properties: (11)

Answer 8

• Colour
• Lustre
• Hardness
• Melting point
• Boiling point
• Ductility
• Malleability
• Conductivity
• Solubility
• Density
• Crystal shape

Question 9

What happens when a substance goes under physical change?

Answer 9

its appearance or state may be altered, but its composition stays the same.

Question 10

Melting point:

Answer 10

is the temperature at which it changes from a solid to a liquid.

• The melting point of ice is 0°C.
• table salt melts at 801°C
• propane melts at 190°C.

Question 11

Boiling point

Answer 11

is the temperature at which its liquid phase changes to the gas phase.

• water’s boiling point is 100°C
• Table salt boils at 1413°C
• propane boils at 42°C.

Question 12

Hardness

Answer 12

is a substance’s ability to resist being scratched

• Hardness is usually measured on the Mohs’ hardness scale from 1 to 10
• mineral talc is the softest substance
• Diamond is the hardest

Question 13

Malleability

Answer 13

A substance that can be pounded or rolled into sheets is said to be malleable
- Aluminum foil

Question 14

Ductility

Answer 14

Any solid that can be stretched into a long wire is said to be ductile
-Copper

Question 15

Crystal shape

Answer 15

The shape of a substance’s crystals can help identify it.

- Salt crystals form cubes.

Question 16

Solubility

Answer 16

is the ability of a substance to be dissolved in another.
- For example, sugar is soluble in
water, but cooking oil is not.

Question 17

Density

Answer 17

is the amount of mass in a given volume of a substance.

• water is 1 g/mL
• gold is 19 g/cm3.

Question 18

Conductivity

Answer 18

is the ability of a substance to conduct electricity or heat

Question 19

A chemical property describes how a substance interacts with other substances such as acids

Chemical Properties :

Answer 19

• reaction with acids
• ability to burn
• reaction with water
• behavior in air
• reaction to heat

Question 20

What is a chemical change?

Answer 20

A chemical change always results in the formation of a different substance or substances.
Ex. Pancakes

Question 21

Pure substance:

Answer 21

A pure substance is made of only one kind of matter and has a unique set of properties that sets it apart from any other kind of matter

• maybe either an element or a compound.
• Examples: Mercury or sugar

Question 22

element:

Answer 22

An element is a material that cannot be broken down into any simpler substance.

• basic building blocks for all compounds.
• elements are organized into a periodic table according to their properties.
• have their own symbols

Question 23

compound:

Answer 23

When two or more elements combine chemically they form a compound.
Ex: hydrogen + oxygen = water

Question 24

mixture:

Answer 24

A mixture is a combination of pure substances

• do not combine chemically as happens when a compound is formed. They remain in their original, pure form, even though they are not always easy to see distinctly once the mixture is made.

Question 25

4 types of mixtures:

Answer 25

Mechanical mixtures, solutions, suspensions, colloids

Question 26

mechanical mixture:

Answer 26

• In a mechanical mixture, the different substances that make up the mixture are visible. (hetergenous)
-Ex. Soil or veggie salad.

Question 27

solution:

Answer 27

In a solution, the different substances that make it up are not separately visible (homogeneous)

Question 28

Type of solutions

Answer 28

• Solid dissolved in liquid- sugar in coffee
• Liquid dissolved in liquid- acetic acid in water(vinegar)
• Gas dissolved in liquid- CO2 in water (carbonated pop)
• Gas dissolved in gas- oxygen in nitrogen (atmosphere)
• Solid dissolved in solid- copper in silver (sterling )

Question 29

aqueous solution:

Answer 29

a substance dissolved in water

- freshwater or vinegar

Question 30

suspension:

Answer 30

A suspension is a cloudy mixture in which tiny particles of one substance are held within another.
-separated with a filter
Ex. Tomato Juice

Question 31

colloid:

Answer 31

A colloid is also a cloudy mixture, but the particles of the suspended substance are so small that they cannot be easily separated.
-Ex. milk and ketchup